1. Field of Invention
The present invention relates to a high voltage device and a manufacturing method of a high voltage device; particularly, it relates to such device and manufacturing method wherein a deep trench isolation structure is provided between a source and a drain of the high voltage device to increase the breakdown voltage.
2. Description of Related Art
FIG. 1 shows a cross-section view of a prior art high voltage device. As shown in FIG. 1, isolation regions 12 are formed in a P-type substrate 11 to define a first device area 100 and a second device area 200. The isolation regions 12 for example are formed by local oxidation of silicon (LOCOS). A gate 13 is formed on the P-type substrate 11. In the first device area 100, an N-type source 14, a P-type body 16, and a P-type body region 17 are formed. In the second device area 200, an N-type drain 15 is formed. And, an N-type well 18 is formed between the source 14 and the drain 15. The high voltage device is usually coupled to a high voltage of tens to hundreds volts during operation; the higher the voltage (i.e., the breakdown voltage) that the high voltage device can sustain, the broader the application of the high voltage device is. To increase the breakdown voltage, a high electric field which is generated by the high voltage in the high voltage device needs to be decreased.
In view of the foregoing, the present invention provides a high voltage device and a manufacturing method of the high voltage device, in which the high electric field generated by a high voltage is decreased to increase the breakdown voltage and to broaden the application of the high voltage device.